A. Introduction. Pregnant sheep will continue to be used for these studies, as they are readily available, are relatively inexpensive (as compared with primates), the fetuses are large enough so that adequate amounts of the several tissues can be studied (cerebral, uterine, and pulmonary arteries, adrenal glands, ef cetera), and we and others have amassed a considerable body of physiologic data on this species. Essentially all of the individual projects in this proposal will use pregnant or nonpregnant sheep which have been acclimatized to high altitude, long-term hypoxemia, or normoxic controls. At the time of sacrifice, tissues from these animals will be partitioned among the several investigators and projects of this proposal, as well as several other investigators. Thus, this Technical Core includes the animals for these studies. In addition, it includes the expense for several major items of equipment required for most of these experiments. The experimental animal and equipment Technical Core will be utilized for essentially every project in common by all members of the Center. Such a Technical Core optimizes the efficient operation of the laboratories, the experiments per se, and the data acquisition and analysis. The essential features of the experimental animal procurement and laboratory are detailed below. Following a general description of our laboratories, equipment, and laboratory animal facilities, the Technical Core will be considered from several aspects: Experimental Animals, White Mountain Research Station, LLU Animal Facilities, Laboratory Core Facilities, and Budget. Drs. Longo and Ducsay will devote 10% of their time to administer the Technical Core. The principal investigators will continue to share major items of equipment including: imaging systems, ultracentrifuges, centrifuges, radioactivity counters, recorders, blood-gas analyzers, analyzers for Western immunoblot, realtime PCR, confocal microscopy, freezers, and other items. In addition, we will continue to share the experimental animals, and surgical operating theater. This fiscally efficient arrangement, together with the scientific collaboration among the investigators js one of the reasons that broad based research support is sought.